Tracking Ivy

By Donny McKnight as told to S. C. Torrington

 

We’d been searching for Ivy in the woods for about an hour. She was only nine-years-old and small for her age. I knew when the Maryland summer got too hot for her; she’d make her way down to the shoreline to cool off. The rest of time you could usually find her napping in her favorite ivy patch.

Suddenly, the receiver beeped louder. We stopped, listened, and heard the familiar slow, steady crunching of leaves. I looked down and there she was. Ivy glared up at me with her beady yellow eyes. Then she pulled her head into her shell and snapped shut her flap.

Ivy is an Eastern Box Turtle (Terrapene carolina carolina). This small reptile lives along the entire U.S. east coast and as far west as Michigan, Texas, and Oklahoma. My grandpa says that when he was a kid, you could find box turtles in neighborhood woods or making their way through backyards. He caught one munching on a low-hanging tomato in his mother’s garden. But I’ve never found a turtle in my yard. Have you?

That’s probably because over the past 60 years, farming and construction has destroyed the turtles’ habitat. Box turtles can live in pastures, meadows, forests, and flood plains. But they love moist areas near fresh water.

The declining number of box turtles is a concern. Their loss would affect their predators like raccoons, minks, and coyotes. Turtles also help to scatter native seeds in its scat (or poop). A healthy turtle population means a healthy environment.

I know all about box turtles. My name is Donny. And I’m a member of a Turtle Telemetry Team. Ever since I was a little kid, I’ve gone into the woodlands with my mom, other naturalists, and volunteers to study them.

Three or four times a week during the summer, my family tracks the movements of 10 turtles that wear tiny radio transmitters glued to their shells. I help to record and date its GPS (Global Positioning System) coordinates. That’s right, we use a GPS just like your family might use for directions in your car.

I also write down the weather, the habitat, and other observations. Young turtles don’t wander very far at all, only about an acre. Adults travel a lot further, averaging about five acres.

In addition to the four females and six males being tracked, almost 90 turtles have been weighed, measured, and each shell has been marked for identification. Scientists use a code system by notching two or three of the sections (scutes) around the shell’s edge with a triangular file. Then all the data is entered in a computer.

“It doesn’t hurt the turtle,” promises Mom. “It’s like getting your fingernails clipped.”

The Eastern Box Turtle has a brown-colored shell with yellow-orange blotches and patterns. The shell is bowl-shaped with hinged flaps like doors that let the turtle pull its head, legs, and tail inside. The turtles’ brown skin varies in color to match winter leaves.

Great camouflage!

Box turtles can live 30 to 50 years, even longer in the wild. We learn their ages by counting the rings (annuli) on the top (carapace) of their shells. After about 20 rings, it’s too hard to count. So, we classify the turtles as juveniles (under 5 years), adults (after 5-8 years), or elders (older than 20 years old).

They stay small—about five to eight inches. Females have brown or yellow eyes. The males’ eyes are usually red. These reptiles are omnivores. That means they’ll eat slugs, earthworms, and insects plus plants, flowers, and berries. Watch out—a turtle’s beak is sharp. And they bite!

Did you know that turtles could catch colds too? One of our transmitter turtles, Charlie, hadn’t moved for a long time. We tracked down and examined him. Charlie’s eyes were sealed shut with mucus. He probably would have died. So Mom brought him home and gave him soaks in warm salt water. I helped to put reptile medicine in his food and water.

At first, Charlie didn’t want to eat. But then I fed him his favorite wild mushrooms. Soon he was eating well. When his eyes were clear, we took Charlie back to his home exactly where we’d found him. He was lucky to be wearing a transmitter!

Heather, another of our GPS turtles, had spent the summer under the sidewalk by the nature center. I was worried. She might be sick like Charlie. Or maybe she’d died. Finally, another volunteer, Gene, helped me to dig her out. Heather was healthy. But she wasn’t happy that we had disturbed her. I let her crawl back under the cool concrete.

One important piece of information is to find out if and where the turtles are laying their eggs. Since we’ve found young turtles, we know they’re breeding. Box turtles often nest in loose soil and organic matter, laying between three and six eggs in the spring. So when one of the females spent much of her time in a mulch pile, we hoped she was nesting. But we never found any signs of eggs.

Then Mom decided to run Thread Surveys to track 12 turtles: six males and six females. A spool of unscented dental floss is put in a small brown pouch. The pouch is attached to the turtle’s shell with brown duct tape. Why do we use a brown pouch and tape? That’s right, camouflage. Don’t worry. The turtle can pull off the pouch if it gets stuck, tangled, or runs out of string.

The end of the thread is tied to a flag or tree. The thread unrolls as the turtle walks. That way we can see exactly where and how far it went. The spool is almost 300 feet long, but since turtles usually travel less than 100 feet a day, the thread can last for several days.

The turtles are checked every few hours. Each time, I flag their position. Another volunteer measures the thread between the flags. According to our data, female turtles take a few more steps than males. Maybe they’re stopping to smell the wild multiflora roses!

Turtles know they’re not safe in the open ground. A coyote could easily see or catch them there. So most of the turtles’ trails run along bushes or vines. Their paths also show leftovers of mushroom, a turtle treat.

Little Ivy likes crispy ivy more than mushy mushrooms. But one day she took a long trip to a tiny strip of woods on a steep hill coated in thorny plants behind a big house. I was afraid someone might find Ivy and keep her as a pet. But I couldn’t help her. As researchers, we’re not allowed to move the turtles. So I was very happy when we finally found her back here in her favorite ivy patch.

I pulled out my field journal to record her data. Ivy still seemed small. Mom said not to worry because box turtles don’t grow much by her age. They do a lot of growing during their first few years when they’re babies.

After I finished the measurements, it was time to put Ivy back in her patch. We quietly waited for her to come out of her shell. That box turtle was very careful. She listened before deciding it was safe to open her flap. Then Ivy poked out her head and looked around. At last, she stuck out her legs and tail, stood up, and turned back to enjoy her green breakfast.

[This story is based on an ongoing research project, initiated in the summer of 2003 by the Anita C. Leight Estuary Center’s Park Manager, to track individual eastern box turtles in the Leight Park, Harford County, Maryland. The ACLEC is the research and education facility of the Otter Point Creek component of the Chesapeake Bay National Estuarine Research Reserve in Maryland.

Donald T. McKnight (“Donny”) is now in college, continues his work at the ACLEC, and recently published his research: Herpetology Notes, volume 4: 097-102 (2011) (published online on 24 March 2011.)]

Vocabulary

Camouflage: To hide by appearing to be part of the natural surroundings.

Field Journal: A science diary in which to record observations, data, drawings.

GPS (Global Positioning System): A system of satellites, computers, and receivers that is able to determine an exact location on Earth.

Habitat: The area where an animal normally lives.

Omnivores: A kind of animal that eats other animals or plants.

Organic Matter: Plant or animal material in various stages of decomposition.

Predators: Animals that live by preying on other animals.

Receiver: An electronic device that picks up communications signals.

Reptile: A cold-blooded, usually egg-laying, vertebrate such as a snake, lizard, or turtle.

Surveys: Data collection tools used to gather information.

Telemetry: The technology of automatic measurement and sending of data by radio from remote sources.

Transmitter: An electronic device that makes a signal and sends it to a receiver.

How You Can Help

  • If you see a turtle crossing the road, please stop to help it. Move it to the side of the road that it was heading and let it go.
  • Do not relocate turtles, even if you think it’s safer. The turtle might try to get back home, causing it to cross roads where it might get killed. Also, relocating turtles can spread diseases and alters the gene pool.
  • Please don’t mark on or take box turtles home as pets. They need to be left in the wild.

Thank You!